The purpose of this quantitative ex post facto study was to determine if a difference exists in academic achievement between low-SES 11th-grade students enrolled or not enrolled in the performing arts of drama or music study at any time between ninth and 10th-grades in the Clark County School District of southern Nevada in the western United States. Four educational theories support this study, including Gardner's theory of multiple intelligences (2011), Bandura's social cognitive theory (1989), Dewey's progressive education (1934), and Deci and Ryan's self-determination theory (2019). The researcher compared the archival ACT composite scores of the four course enrollment groups of drama, music, both drama and music, and no-performing arts courses. The sample consisted of 548 students from a single 100% free and reduced lunch (FRL) high school in southern Nevada. For the first research question, the researcher rejected the null hypothesis as the results showed a statistically significant difference between course enrollment groups, F(3, 544) = 6.833, p < .0005. Pairwise comparisons determined a statistically significant difference in mean ACT composite scores between students who took no-performing arts courses and those who took either music (p = .007) or both drama and music (p = .001). By providing quantitative data on the performing arts of music and drama, this research supports educators and leaders in making data-driven decisions that best support the academic achievement of their high school student populations. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]